US4121421A - Hydraulic brake booster having charging and check valves - Google Patents

Hydraulic brake booster having charging and check valves Download PDF

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Publication number
US4121421A
US4121421A US05/757,263 US75726377A US4121421A US 4121421 A US4121421 A US 4121421A US 75726377 A US75726377 A US 75726377A US 4121421 A US4121421 A US 4121421A
Authority
US
United States
Prior art keywords
accumulator
inlet port
pressure chamber
stem
charging valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/757,263
Other languages
English (en)
Inventor
Bruce B. Myers
Robert W. Jackson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bendix Corp
Original Assignee
Bendix Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bendix Corp filed Critical Bendix Corp
Priority to US05/757,263 priority Critical patent/US4121421A/en
Priority to GB53202/77A priority patent/GB1556967A/en
Priority to IT31329/77A priority patent/IT1089736B/it
Priority to AU32120/78A priority patent/AU513455B2/en
Priority to AR270626A priority patent/AR214112A1/es
Priority to FR7800158A priority patent/FR2376780A1/fr
Priority to MX171940A priority patent/MX150014A/es
Priority to ES465789A priority patent/ES465789A1/es
Priority to JP53000300A priority patent/JPS5820821B2/ja
Application granted granted Critical
Publication of US4121421A publication Critical patent/US4121421A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
    • B60T13/14—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using accumulators or reservoirs fed by pumps
    • B60T13/142—Systems with master cylinder
    • B60T13/143—Master cylinder mechanically coupled with booster

Definitions

  • a hydraulic brake booster pressurized fluid from an inlet port is communicated to an accumulator.
  • the pressurized fluid is also communicated upon operator actuation of a spool valve to a pressure chamber wherein the pressurized fluid urges a piston to move within the hydraulic brake booster housing to effect a brake application.
  • the hydraulic brake booster housing In order to charge the accumulator and to communicate the accumulator with the pressure chamber, the hydraulic brake booster housing includes a bore extending from the inlet port to the pressure chamber and intersecting the accumulator. Within this bore are disposed a charging valve and a check valve.
  • the charging valve of the prior art communicates pressurized fluid from the inlet port to the accumulator when the force of the pressure at the inlet port is greater than the force of the pressure within the accumulator plus the resilient force of a spring urging the charging valve to a closed position.
  • the check valve of the prior art normally closes communication between the accumulator and the pressure chamber as a result of the force of the pressure within the accumulator and the resilient force of the spring urging the check valve to a closed position.
  • the present invention is an improvement in the hydraulic brake booster charging and check valves of the prior art.
  • the charging valve is slidably mounted in a hydraulic brake booster housing bore that extends from the inlet port to the pressure chamber and intersects the accumulator.
  • the check valve is fixedly disposed within the housing bore to limit the axial movement of the charging valve from a transverse face on the housing bore to the check valve.
  • the check valve includes a stem that is slidably mounted in a passage extending through the check valve. The stem is pressure responsive such that a ball at one end closes the passage and an operator actuating means is engageable with the other end to open the check valve passage.
  • the charging valve includes a slot for receiving the stem.
  • the housing bore includes a tapered shoulder that is substantially parallel with a tapered edge on the charging valve and the edge and shoulder engage a sealing ring having frusto conical surfaces substantially parallel with the tapered shoulder and edge to seal the charging valve to the housing bore.
  • the check valve comprises a metal sleeve that is sealingly engaged with the housing bore and a plastic insert that is sealingly engaged with the sleeve.
  • the insert forms the passage within which the stem is slidably mounted and the sleeve forms an abutment for engaging the charging valve to limit the axial travel of the charging valve in one direction.
  • the charging valve comprises a plastic shell forming a radial clearance with the housing bore so that movement of the shell away from either the sealing ring or the tapered shoulder permits fluid flow through the housing bore around the shell.
  • FIG. 1 is a schematic view of a hydraulic brake booster system showing the booster partly in cross section;
  • FIG. 2 is an enlarged view of the encircled portion of FIG. 1;
  • FIG. 3 is a view similar to FIG. 2 with the charging valve abutting the check valve.
  • a hydraulic brake booster is illustrated in general in FIG. 1 by the numeral 10.
  • the booster is connected via suitable conduit means to a pump 12 and a steering gear 14.
  • An inlet port 16 communicates pressurized fluid from the pump 12 to the booster housing 18 while an outlet port 20 communicates pressurized fluid from the booster housing 18 to the steering gear 14 and a return port 22 communicates pressurized fluid back to the pump 12.
  • the hydraulic brake booster housing 16 includes a pair of bores 24 and 26 for slidably receiving a piston 28 and a spool valve 30, respectively.
  • the piston 28 is connected to a rod 32 which extends from the booster housing 18 to operatively engage a master cylinder (not shown) on the left of the housing.
  • the bore 26 intersects the inlet port 16, the outlet port 20 and the return port 22 and the spool valve 30 cooperates with these ports to communicate the inlet port 16 with the outlet port 20 when the spool valve 30 is in one position and to communicate the inlet port 16 with a pressure chamber 34 when the spool valve is moved to a second position, as is well known in the art.
  • a rod 36 extends from a blind bore 38 in the piston 28 and is operatively connected to a brake pedal (not shown).
  • a lever 40 is pivotally connected to a bracket 42, which is attached to the piston 28, to the spool valve 30 via a flange 44, and to a collar 46 which is slidingly carried on the rod 36 and biased to the left via spring 48.
  • the hydraulic brake booster housing 18 includes a stepped bore 50 that extends from the inlet port 16 to the pressure chamber 34 and intersects an accumulator path 52 which communicates with an accumulator 54, illustrated in FIG. 1, via a port 56 opening to the accumulator 54.
  • a charging valve 60 and a check valve 62 are disposed within the stepped bore 50.
  • the check valve 62 is held within the stepped bore 50 by means of the overlap at 64 provided by the housing cover 66, which overlap abuts the check valve to maintain the same within the stepped bore 50.
  • the charging valve 60 is slidably mounted in the stepped bore 50 between a transverse face 68 on the stepped bore and the check valve 62.
  • the charging valve 60 carries a relief valve 69 in the form of a ball 70 which is biased by spring 72 against the plug 74 to close the plug opening 76.
  • the plug is press fitted or secured by other suitable means to the cylindrical shell 78 of the charging valve 60.
  • a slot 80 on the plug 74 communicates with an opening 76 and another opening 77 communicates the inlet port to the interior of the shell 78.
  • a stem 82 is slidably carried in the passage 84 which extends through the check valve 62.
  • a ball 86 on one end of the stem 82 is engageable with the check valve to close the passage 84.
  • the ball 86 and the stem 82 extend into the slot 80 on the charging valve 60 so that the charging valve 60 can abut the check valve 62 without interfering with the opening of passage 84 when the stem 82 and ball 86 move to the left viewing FIG. 3.
  • a sealing ring 94 is disposed between the tapered shoulder 90 and the tapered edge 92 and the sealing ring 94 includes a frusto conical inner surface 96 and a frusto conical outer surface 98 that are substantially parallel to the shoulder and edge.
  • the check valve 62 comprises a sleeve 100 with another recess carrying a sealing ring 102 and inner recesses for receiving a portion of an insert 104 to sealingly fix the insert 104 to the sleeve.
  • the shell 78, the plug 74 and the insert 104 are formed from a thermoplastic material such as nylon so that these parts can be injection molded.
  • the plastic insert 104 is injection molded into the "mold" formed by the sleeve 100 which can be made of a harder material such as aluminum. It is seen in FIG. 2 that the plug 74 abuts the sleeve 100 as well as the insert 104 when the charging valve 60 moves to the right. Therefore, the abutment between the plug 74 and the sleeve 100 prevents the plug from disforming the plastic insert 104 when in abutment therewith.
  • the hydraulic brake booster 10 operates in a conventional manner to provide a power assist to a brake application.
  • the rod 36 is urged to the left to pivot the operator actuator 40 about the pivot on bracket 42. Consequently, the pivotal connection with flange 44 moves the spool valve 30 to the left to communicate pressurized fluid from the pump 12 to the pressure chamber 34 via inlet port 16 and the passage through spool valve 30.
  • the increase in pressure in chamber 34 urges the piston to the left to operatively engage the rod 32 with the brake master cylinder to effectuate a brake application.
  • the operator actuator 40 pivots about the connection with flange 44 to urge the bracket 42 and piston 28 to the left to effectuate a manual brake application.
  • the accumulator 54 is charged with pressurized fluid from the inlet port whenever the pressure in the inlet port is greater than the pressure in the accumulator 54 or passage 52.
  • the larger pressure on the left of charging valve 60 urges the shell 78 and plug 74 to the right, viewing the Figures, away from the sealing ring 94 until the plug 74 abuts the sleeve 100 and insert 104. Consequently, pressurized fluid is communicated through the radial clearance between the shell 78 and the housing bore 50 to the passage 52 and the accumulator 54.
  • the slot 80 receives the ball 86 of the stem.
  • a decrease in the pressure in the accumulator 54 below the inlet port pressure causes the charging valve to open the inlet port to the accumulator 54 and to the pressure chamber 34 when the flange is engaged with the stem 82.
  • the slot 80 is axially dimensioned to receive the stem 82 and the ball 86 when the charging valve 60 is in abutment with the check valve 62, as illustrated in FIG. 3. Therefore, the charging valve 60 moves axially in bore 50 independently of the position of the stem 82.
  • the charging valve is responsive to the inlet port pressure to move away from sealing ring 94 to communicate the pressurized fluid from the inlet port to the pressure chamber via the clearance between shell 78 and bore 50, the slot 80 and the open passage 84.
  • the slot 80 exposes the accumulator 54 to the pressure relief valve 69 regardless of the axial position of the charging valve 60 within the bore 50. This prevents excessive buildup and storage of pressurized fluid within accumulator 54.

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Braking Systems And Boosters (AREA)
  • Valves And Accessory Devices For Braking Systems (AREA)
US05/757,263 1977-01-06 1977-01-06 Hydraulic brake booster having charging and check valves Expired - Lifetime US4121421A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US05/757,263 US4121421A (en) 1977-01-06 1977-01-06 Hydraulic brake booster having charging and check valves
GB53202/77A GB1556967A (en) 1977-01-06 1977-12-21 Hydraulic boost device
IT31329/77A IT1089736B (it) 1977-01-06 1977-12-28 Servofreno idraulico
AU32120/78A AU513455B2 (en) 1977-01-06 1978-01-03 Hydralic boost device
AR270626A AR214112A1 (es) 1977-01-06 1978-01-04 Dispositivo servo hidraulico,en especial para frenos
FR7800158A FR2376780A1 (fr) 1977-01-06 1978-01-04 Perfectionnements aux amplificateurs de freinage
MX171940A MX150014A (es) 1977-01-06 1978-01-04 Mejoras en dispositivo elevador de freno hidraulico para vehiculos
ES465789A ES465789A1 (es) 1977-01-06 1978-01-05 Perfeccionamientos en dispositivos intensificadores hidrau- licos para frenos de vehiculos.
JP53000300A JPS5820821B2 (ja) 1977-01-06 1978-01-06 流体倍力装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/757,263 US4121421A (en) 1977-01-06 1977-01-06 Hydraulic brake booster having charging and check valves

Publications (1)

Publication Number Publication Date
US4121421A true US4121421A (en) 1978-10-24

Family

ID=25047108

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/757,263 Expired - Lifetime US4121421A (en) 1977-01-06 1977-01-06 Hydraulic brake booster having charging and check valves

Country Status (9)

Country Link
US (1) US4121421A (fr)
JP (1) JPS5820821B2 (fr)
AR (1) AR214112A1 (fr)
AU (1) AU513455B2 (fr)
ES (1) ES465789A1 (fr)
FR (1) FR2376780A1 (fr)
GB (1) GB1556967A (fr)
IT (1) IT1089736B (fr)
MX (1) MX150014A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199946A (en) * 1978-03-03 1980-04-29 The Bendix Corporation Integrated control for brake and steering systems
US4756160A (en) * 1985-11-26 1988-07-12 Automotive Products Plc Hydraulic master cylinder
US5185999A (en) * 1991-10-18 1993-02-16 Allied-Signal Inc. Hydraulic brake booster and valve members
US20080245793A1 (en) * 2007-04-05 2008-10-09 The Coleman Company, Inc. Insulated container with foot-operated lid

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3638528A (en) * 1970-06-17 1972-02-01 Bendix Corp Hydraulic boost device with auxiliary fluid supply
US3889467A (en) * 1974-06-24 1975-06-17 Midland Ross Corp Accumulator arrangement for a booster brake mechanism
DE2507588A1 (de) * 1974-02-22 1975-08-28 Bendix Corp Hydraulischer kraftverstaerker mit darin integriertem kraftspeicher
US3955597A (en) * 1973-11-07 1976-05-11 Shoketsu Kinzoku Kogyo Kabushiki Kaisha Poppet type change-over valve assembly

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50144320U (fr) * 1974-05-17 1975-11-28

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3638528A (en) * 1970-06-17 1972-02-01 Bendix Corp Hydraulic boost device with auxiliary fluid supply
US3955597A (en) * 1973-11-07 1976-05-11 Shoketsu Kinzoku Kogyo Kabushiki Kaisha Poppet type change-over valve assembly
DE2507588A1 (de) * 1974-02-22 1975-08-28 Bendix Corp Hydraulischer kraftverstaerker mit darin integriertem kraftspeicher
US3889467A (en) * 1974-06-24 1975-06-17 Midland Ross Corp Accumulator arrangement for a booster brake mechanism

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199946A (en) * 1978-03-03 1980-04-29 The Bendix Corporation Integrated control for brake and steering systems
US4756160A (en) * 1985-11-26 1988-07-12 Automotive Products Plc Hydraulic master cylinder
US5185999A (en) * 1991-10-18 1993-02-16 Allied-Signal Inc. Hydraulic brake booster and valve members
US20080245793A1 (en) * 2007-04-05 2008-10-09 The Coleman Company, Inc. Insulated container with foot-operated lid

Also Published As

Publication number Publication date
ES465789A1 (es) 1978-09-16
AU513455B2 (en) 1980-12-04
AR214112A1 (es) 1979-04-30
AU3212078A (en) 1979-07-12
FR2376780A1 (fr) 1978-08-04
JPS5820821B2 (ja) 1983-04-25
MX150014A (es) 1984-03-02
IT1089736B (it) 1985-06-18
GB1556967A (en) 1979-12-05
JPS5385271A (en) 1978-07-27
FR2376780B1 (fr) 1981-12-04

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